Comment by jeroenhd

It does: https://github.com/adryd325/oneko.js/blob/main/oneko.js

       const isReducedMotion =
         window.matchMedia(`(prefers-reduced-motion: reduce)`) === true ||
         window.matchMedia(`(prefers-reduced-motion: reduce)`).matches === true;
     
       if (isReducedMotion) return;
     

Simple but effective. More websites should include this check. Well done, adryd325!